TOKYO -- Even as Japan begins cranking up its nuclear reactors again, Tokyo has launched a scheme it hopes will spark a green-energy revolution and put the country at the leading edge of renewables.

New rules oblige utilities to buy all electricity produced from renewable sources, including solar, wind and geothermal power, at above-market rates for the next two decades, in a bid to stoke "green" power investment.

Advocates say the rush by suppliers to capitalize on the scheme could nearly double demand for solar cells this year alone, spurring economies of scale for panel producers and ultimately bringing down the cost of renewable energy.

The scheme comes as Japan debates its future energy policy, and is squarely aimed at forcing change in the way Japan's enormous — and powerful — utility companies operate.

The tsunami-sparked meltdowns at the Fukushima nuclear plant in March last year led to the shuttering of Japan's entire stable of reactors.

They forced Tokyo to turn to expensive fossil fuels to replace the third of the country's electricity the atomic plants had produced.

Analysts say despite public fears, nuclear is here to stay for the foreseeable future, but resource-poor Japan must rebalance its energy mix and make greater use of renewables.

The so-called feed-in tariff could spur a whopping 85-percent rise in solar cell demand in Japan this year alone, according to Nomura Securities, and "trigger a full-scale launch of large solar farms in Japan".

"New solar cell installation could expand further if the uptake of inexpensive, Chinese-made solar cells accelerates," Nomura analyst Kyoichiro Yokoyama said in a research note.

The amount of new solar power capacity that Nomura predicts for Japan this year is equal to about two nuclear reactors.

"I want to use it as a trigger to fuel the use of renewable energy," Industry Minister Yukio Edano said recently.

"It is clear that additional cost is necessary to promote greater use of renewable energy and to end our reliance on nuclear plants as soon as possible," he added.

Japan gets less than 2 percent of its power from renewable sources, rising to about 10 percent including hydroelectric power, but still below other industrialized nations.